Complete Story 1-1 and fix TypeScript issues

Add TypeScript strict mode and typecheck tasks to monorepo infrastructure.
Fix E2E test @payload-config alias and frontend TypeScript errors.

- Add tsconfig.json to backend with strict mode and path aliases
- Add typecheck task to Turborepo and all packages
- Fix @payload-config alias for E2E tests and dev server
- Add setToken method to AuthService for middleware use
- Fix implicit any types in Footer.astro and Header.astro
- Remove invalid typescript config from astro.config.mjs

packages/shared/tsconfig.json

@@ -5,10 +5,17 @@
     "declarationDir": "dist",
     "emitDeclarationOnly": true,
     "module": "ES2020",
-    "moduleResolution": "Node",
+    "moduleResolution": "Bundler",
     "target": "ES2020",
     "rootDir": "src",
-    "outDir": "dist"
+    "outDir": "dist",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedIndexedAccess": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true
   },
   "include": ["src/**/*"]
 }